The Last Stones

No levels. No classes.
You get better at what you do. Swing a sword and your sword skill goes up. Cast fire and your fire gets stronger. Your character is whatever you spent your time on.
In the footage: Osric fights a wolf at midday. Sharp goes from 3 to 6.
Animals live their own lives
Wolves hunt deer. Some creatures only come out at night. They listen as well as look, so making noise can bring something to you.
In the footage: Just before dawn, a wolf runs down a deer and eats it.
Some ruins need friends
Under the ground are the ruins of an old city. Some floors only open when enough people stand on the plates at once, and some guardians are too strong for one person.
In the footage: Osric stands on the plate to open the door. Wren goes in to the cyclops.
The world changes
Trees burn down. Rivers freeze, and you can walk across them. What you change above ground stays changed.
In the footage: Two players cast Flame at a line of trees as night falls.
Phone or computer
It runs in the browser. Same world, same people, whichever you pick up. Start on a laptop and carry on from your phone.
In the footage: Wren outside the Gilded Barrel, on a phone and on a laptop.

The story

A people called the Arcane learned to command nature by writing on stones. Twelve of them tried a stone meant to open a door to another world. It joined the two worlds into one instead, and what lived on the other side came through.
Three survived. Garius froze their city in time, so every sixty days it goes back to how it was. Dieter made new people, us, who remember what happens. Holleg turned himself into forty metres of earth and buried it all.
People still call the ground Holleg. You wake up in the one room left near the surface, where Dieter is writing the story on the wall.

A small MMO that runs in your browser.